Disk drive including an actuator main coil and an actuator secondary coil with a lateral segment and method of operating same
View Patent ↗A disk drive includes a magnetic element having first and second magnets extending radially with respect to an axis of rotation of an actuator. The disk drive further includes a main coil. The main coil includes first and second radial segments. The first radial segment overlaps the first magnet throughout a full range of motion of the actuator. The second radial segment overlaps the second magnet throughout the full range of motion of the actuator. The disk drive further includes a secondary coil which is separately energized from the main coil. The secondary coil is configured to produce magnetic forces upon the actuator substantially parallel to the actuator longitudinal axis. The secondary coil includes a lateral segment disposed perpendicular to the actuator longitudinal axis and overlapping the first and second magnets throughout the full range of motion of the actuator.
1. A disk drive comprising:
a disk drive base;
an actuator rotatably coupled to the disk drive base and defining an actuator longitudinal axis orthogonal to the axis of rotation, the actuator including an actuator body configured to pivot about an axis of rotation and a coil support extending from the actuator body;
a magnetic element coupled to the disk drive base, the magnetic element including first and second magnets extending radially with respect to the axis of rotation;
a main coil attached to the coil support, the main coil including first and second radial segments, the first radial segment overlapping the first magnet throughout a full range of motion of the actuator, the second radial segment overlapping the second magnet throughout the full range of motion of the actuator; and
a secondary coil attached to the coil support, the secondary coil being separately energized from the main coil, the secondary coil being configured to produce magnetic forces upon the actuator substantially parallel to the actuator longitudinal axis, the secondary coil including a lateral segment disposed perpendicular to the actuator longitudinal axis and overlapping the first and second magnets throughout the full range of motion of the actuator.
2. The disk drive of claim 1 wherein the main coil includes a main coil outer transition segment electrically connecting the first and second radial segments, the magnetic element defines a magnet periphery, the main coil outer transition segment is disposed overlapping the magnetic element beyond the magnet periphery.
3. The disk drive of claim 2 wherein the secondary coil is disposed within the main coil.
4. The disk drive of claim 2 wherein the secondary coil includes a secondary coil outer transition segment electrically connected to the lateral segment, the secondary coil outer transition segment is disposed overlapping the magnetic element beyond the magnet periphery.
5. The disk drive of claim 1 wherein the main coil includes a main coil outer transition segment electrically connecting the first and second radial segments, the magnetic element defines a magnet periphery, the main coil outer transition segment is disposed overlapping the magnetic element within the magnet periphery.
6. The disk drive of claim 5 wherein the main coil outer transition segment is arc-shaped and is defined by a radius from the axis of rotation.
7. The disk drive of claim 5 wherein the lateral segment is disposed radially further than the main coil with respect to the axis of rotation.
8. The disk drive of claim 1 wherein only a selected one of the main coil and the secondary coil is energizable at any given time.
9. The disk drive of claim 1 wherein the main coil is configured to be energized during track seeking operations, the secondary coil is configured to be energized during track follow operations.
10. The disk drive of claim 9 wherein the main coil is configured to be not energized during track follow operations.
11. A method of operating a disk drive, the disk drive including an actuator defining an actuator longitudinal axis orthogonal to an axis of rotation, the disk drive further including a magnetic element including first and second magnets extending radially with respect to the axis of rotation, the method comprising:
a) energizing a main coil during track seek operations of the disk drive, the main coil including first and second radial segments, the first radial segment overlapping the first magnet throughout a full range of motion of the actuator, the second radial segment overlapping the second magnet throughout a full range of motion of the actuator; and
b) energizing a secondary coil during track follow operations of the disk drive, the secondary coil being separately energized from the main coil, the secondary coil being configured to produce magnetic forces upon the actuator substantially parallel to the actuator longitudinal axis, the secondary coil including a lateral segment disposed perpendicular to the actuator longitudinal axis and overlapping the first and second magnets throughout the full range of motion of the actuator.
12. The method of claim 11 wherein the main coil is not energized during track follow operations.